Relief print



Aug. 23, 1938. J. J, TlGHE RELIEF PRINT Filed July 50, 1934 INVENTORJo/zrz 7 TTORNEY i,

Patented Aug. 23, 1938 r TED STATE eA'rsr orFitcE RELIEF PRINT ofMassachusetts Application July 30, 1934, Serial No. 731483 8 Claims.

The invention relates to prints, lithographs, androtographs, includingink or color impressions and similar productions, and with regard to itsmore specific features to the simulation of anabrasive, such as agrinding wheel, in a picone object of the invention is to provide anefiicient printingprocess whereby finely divided matter-maybeincorporated with a printing ink. Another object of the invention isto provide a process for attaching-comminuted matter, for

.illustrative purposes, to a sheet of paper. Another object of theinvention is to unite comminuted matter such as crystal grains to papertogether with inks in various shades in order to makea more realisticpicture of an article than can'be achieved by inks or photographicprocess alone." 'Another object of the invention is to provideanefficient and reliable process of the nature referred to. Another objectof the invention is to producea printed sheet presenting an extremelyrealistic picture of an article having a roughened, reflective, orgritty appearance. Another object ofthe invention is'to provide ang5iillustration incorporating comminuted matter held in place by atransparent or translucent binder which-maybe superimposed over a firstprinting to produce a detailed picture. Other objects will be inpartobvious or in part pointed 30 out hereinafter.

The invention-accordingly consists in the features of construction,combinations of elements, arrangements of parts, and in the severalsteps and relation and order of each of said steps to one or'rnore oftheothers thereof, all as will be uillustratively described herein, and thescope of the application of which will be indicated in the followingclaims.

In the accompanying drawing, in which is shown one of various possibleembodiments of the mechanical features of thisinvention,

Figure'l is'a picture of a grinding wheel to illustrate my process andthe print or impression produced thereby;

Figure 2 is a cross-sectional view through a sheet of paper havingthe'picture of Figure 1 produced according to my novel process thereon,with the parts greatly'magnified and without being drawn to exact scale.

Similar reference characters. refered to similar parts throughout theseveral views of the draw- In performing the process of my invention Iset up a printing-pressto produce a background on the paper which is-t0be printed. This background may be any picture, with or Without words,and produced according to anyknown printing process. Referring now toFigures 1 and 2, apiece of paper which has been put through the press isindicated at H], and has superim--"-5 posed thereon a general backgroundH which may be plain or may include a picture or Words. The picturewhich is more particularly the subject matter of the invention isgenerally designated at l2 and in this embodiment is a grinding"l0wheel. The original or first printing or background includes dark placesI 3 which represent the shading or darker surfaces in the-picture of"the grinding wheel.

Having produced the desired number of sheets l5 by printing thebackground I I and the shaded parts 63 on an ordinary press, or havingproduced the same kind of a picture by means of a 'rotogravure processor the like, the sheets-I0 are ready for the second part of the process.The-20 press is again set up, but this time with merely a'flat tintplate which is exactly the size and shape of the area of the outline ofwheel l2 in the ultimate picture in the press to contact with that partof each sheetwhich is to have the picture of the wheel. This press isthen run and the tint plates are inked with an-ink adapted to withstandhigh temperatures such as are used in the later part of the process ashereinafter described. The ink used in the press forthe secondw ortint'plateprinting may betransparent, white, red, gray or any desiredcolor, andthe pigment used, if any, is preferably a dry pigment in anycolor, or'carbon or lamp black for the darker shades, and this iscombined with a vehicle i adapted to withstand high temperatures. Thevehicle I prefer to useis a mixture of castor oil and resin gum. Othervehicles adapted to withstand the effects of hightemperatures may beused, but I note that the rosin gum has particular e advantages inconnection with the specific resin that I prefer to use as hereinafterspecified.

The press having been set up for the second or tint plate printing, andthe rollers inked with atherrnographic ink of the nature specified, the1 sheets it which have had the background printing are put through thepress one-by one. As they come out of the press, one by one, and while'the'tint plate printing I4 is still wet, the sheets are sprinkled witha mixture of a com- 350 minuatc'd binder which will melt at temperaturesthat will not burn the paper and a comminuted irregular hard substance.For the binder I prefer to use comminuted or powdery rosin, particular-.ly 'as this, upon heating, combines very'effective- F ly with the rosinin the ink. Furthermore, when melted, rosin readily flows and itsviscosity is such that it forms a coating around the hard particles, andit is transparent and virtually colorless in itself and hence assumesthe color of the ink. It is also very adherent, binds the entire massincluding the hard comminuted substance together and holds it firmly tothe paper It. The rosin is indicated at in the drawing and has embeddedtherein the hard comminuted particles It.

For the latter I prefer to use grains of alumina, such as grit soldunder the trade-mark Alundum. I may, if I desire, use silicon carbidegrains, such as the grit sold under the trade mark Crystolon. I may alsouse other crystalline grains, such as quartz or the like, and forcertain embodiments of the invention other comminuted matter may beused. For the specific size of grains used in a preferred embodiment ofthe invention I mention a mixture of 50 per cent -grit grains and 50 percent -grit grains.

While various proportions of the mixture of resin and hard comminutedsubstances may be adopted, when rosin and alumina are used I find amixture of two parts of rosin to one part of alumina grit, by volume, tobe highly desirable and efiicacious in practical use. By using thisproportion, the background of the picture shows through very effectivelyso that written matter is entirely legible through the coating, asillustrated in Figure 1. By crystalline grain I intend to define suchcompounds, both natural and artificial, as have a crystalline fractureand appearance to the naked eye and excluding all pure metals or alloysof metals and other substances which may be ductile and which incomminuted form do not present a crystalline appearance to the eye,although they may be crystalline in fact under the microscope. Thisinvention is in the field of illustration and characteristics which areimportant relate to the appearance of the substance. Furthermore I usecomminuted substances the individual particles of which can be seen andwhich give the abrasive appearance to the printed sheet, and finelydivided materials which look like a mere powder are sharplydistinguishable as their effect is merely that of a filler.

A mixture of binder and hard comminuted material having been dusted ontothe sheets 10 successively, they are then tapped and shaken and themixture will be found to adhere to the tint plate printing I 4, but themixture on the remainder of the paper will fall back into the box orother receptacle provided for the purpose. It should be noted that eachsheet is dusted and then shaken right after it comes from the tint plateprinting operation.

The sheets are now'ready for the final heattreatment and steps in theprocess which complete the article.

I prefer to carry out the printing operation on a machine having anapron which moves through a heater. I may use a machine of the typedisclosed in United States Letters Patent to H. J. Smith, No. 1,025,594,and hence I have not illustrated such machine and need not describe itin detail herein. Instead of the apron comprising transverse Wire rods24 shown in this patent to Smith, I prefer to use an asbestos or canvasbelt, in order to prevent the paper from being burned. Instead of a longburner tube 42 extending in the direction of movement of the apron asshown in the patent to Smith, I prefer to use a plurality of burnertubes extending transversely of the direction of movement of the apron,and instead of locating holes on the upper part of the tube or tubes, Iprefer to have the flame holes on the under side of the tubes. Withthese changes I may use the mechanism of said Smith patent, or any otherapparatus which will give the heat treatment to be described.

On the moving apron of such a machine I place the sheets treated asalready described, one by one. The machine preferably has a hood such asthe hood H! of the patent to Smith, and this hood or hot box may beapproximately 18 feet long. I may feed the sheets through it at the rateof about 1,000 sheets an hour. The flames are adjusted such as by avalve like the valve 45 of the patent to Smith referred to so that theflames extend down toward but do not quite touch the paper as the sheetsare run through. If the final product has a rubbery surface I know thatthe temperature in the hot box or hood is excessive, and I maintain theheat in the hot box as high as possible without making the final productrubbery.

The temperature in the hot box should be high enough to melt the rosinand cause it to flow sufficiently to embed all of the comminutedparticles. Within the limits as suggested, different temperatures may beused, and I note that very practical results have been obtained when thetemperature over the burner tubes in the hot box was of the order of 400deg. to 450 deg. Fahrenbelt.

I may print pictures in different colors on a single sheet of paper atone operation of the tint shaded areas, writing of any words, and even;

different colors in different parts of the same article. In other wordsthe process is adapted to produce any desired picture at all, in anycolor. The picture differs from other pictures, however, in beingextremely realistic in any case where it is desired to produce theeffect of a broken rough surface, as the individual grains of comminutedmatter, for example alumina, scatter the light and offer reflectivesurfaces which sparkle. Furthermore, sparkling points scatter light inall directions, so that the picture is effective viewed at any angle andeffects other than the mirrorlike result of a metal plating process canbe achieved. My product thus differs from the prior products in whichflakelike particles of metal incorporated in a binder present a surfacewhich reflects a beam of light at a single dihedral angle or incident.The comminuted material which I use, however, is preferably alive andsparkles.

Not only grinding wheels, but abrasives of all descriptions may berepresented by my process,

and such things as brick buildings very effectively portrayed. It wouldbe impossible for me to give even a small fractional part of thepossible articles and things which can be effectively portrayed by myinvention. The process may be varied for different mixtures of ink anddifferent grades of paper not only by adjusting the burners but also bycontrolling the speed of the driving motor such as by the use of therheostat 48 and controller handle 49 shown in the patent to Smithreferred to.

I find that the product is much improved by cooling the sheets fairlyrapidly as they come out of the hot box. Furthermore this allows thesheets to be stacked without having them stick together. Therefore, Iprefer to use an electric fan, preferably located above the apron anddirecting a blast of relatively cool air onto the sheets to cool themquickly to a temperature that permits of handling them and avoids thepossibility of their sticking together.

Without limiting the generality of the foregoing, I note that while Ihave described the process and the article in connection with paper, Imay in certain cases use cloth or other backing. Furthermore, althoughthe principal use now contemplated for the invention is that of theillustration or picturization of something, I contemplate that thearticle and the process may have other uses and no limitation should beimplied to the invention other than those expressed in the followingclaims.

It will thus be seen that there has been provided by this invention amethod and article in which the various objects hereinabove set forth,together with many thoroughly practical advantages are successfullyachieved. As various possible embodiments might be made of themechanical features of the above invention and as the art hereindescribed might be varied in various parts, all without departing fromthe scope of the invention, it is to be understood that all matterhereinbefore set forth or shown in the accompanying drawing is to beinterpreted as illustrative and not in a limiting sense.

1. The combination with a sheet of paper, an ink imprint thereon, and abinder on said ink imprint, of crystalline grain of sufficient grit sizethat individual particles are visible to the naked eye, embedded in saidbinder, the binder covering the grain so that it is not exposed.

2. The combination with a sheet of paper and an ink imprint thereon, ofa binder of rosin on said ink imprint and crystalline grain ofsufficient grit size that individual particles are visible to the nakedeye, in said rosin, the rosin covering the grain so that it is notexposed.

3. The combination with a sheet of paper, and a resinous thermographicink imprint thereon, of a rosin binder on said ink imprint, andcrystalline grain of sufiicient grit size that individual particles arevisible to the naked eye, in said binder, the binder covering the grainso that it is not exposed.

4. The combination with a sheet of paper, and an ink imprint thereon, ofa transparent binder united to said ink and crystalline grain ofsufficient grit size that individual particles are visible to the nakedeye, in said binder, the binder covering the grain so that it is notexposed.

5. The combination with a sheet of paper, an ink imprint thereon, and. abinder on said ink imprint, of grains of alumina in said binder, thebinder covering the grain so that it is not exposed.

6. The combination with a sheet of paper, an ink imprint thereon, and abinder on said ink imprint, of grains of crystalline grain of sufficientgrit size that individual particles are visible to the naked eye, insaid binder, the binder covering the grain so that it is not exposed.

7. The combination with a sheet of paper, of a first printing forming apattern, design or picture, a second solid color printing over saidfirst printing, a translucent binder adhering to said second printing,and crystalline grain of sufiicient grit size that individual particlesare visible to the naked eye, in said binder, the binder covering thegrain so that it is not exposed.

8. The combination with a flexible fabric, of a coating secured theretocomprising crystalline grain of suflicient grit size that individualparticles are visible to the naked eye, embedded in rosin, the rosincovering the grain so that it is not exposed.

JOHN J. 'IIGI-IE.

